Question

A signal is processed by a causal filter with transfer function \( G(s) \). For a distortion-free output signal waveform, \( G(s) \) must

• A. Provide zero phase shift for all frequencies
• B. Provide constant phase shift for all frequencies
• C. Provide linear phase shift that is proportional to frequency
• D. Provide a phase shift that is inversely proportional to frequency

Hint:

Linear phase filters preserve the shape of the signal waveform by ensuring all frequency components are delayed equally.

Answer 1

The Correct Option is C

For a system to process a distortion-free signal, the phase shift introduced by the filter must be linear and proportional to frequency. This ensures that all frequency components of the signal are delayed by the same amount and do not distort the shape of the waveform. Therefore, the correct answer is option (3).